The American Idol runner-up sold 121,204 digital copies of the song and also entered Billboard's Hot 100 chart at No. 20, the highest numbers for a second place Idol act in six years.
Alaina told AOL's The Boot: "This is so awesome! American Idol has changed my life, so I'm excited that the songs I performed on there are doing so well.
"I can't believe that I have a song out on country radio, much less that so many stations started playing it right away. I can't wait to get out and meet everybody and thank them personally for playing my song."
The 16-year-old went on to explain the personal significance behind 'Like My Mother Does', adding: "My mum has been beside me through this whole thing. She has been my biggest cheerleader and my biggest supporter when I was feeling down. This song is for her."
Alaina has insisted that she is still the same girl as before her American Idol experience and said that the show has not changed who she is at heart.